@@ -147,6 +147,41 @@ instrument_copy_from_user_after(const void *to, const void __user *from,
kmsan_unpoison_memory(to, n - left);
}
+/**
+ * instrument_memcpy_before - add instrumentation before non-instrumented memcpy
+ * @to: destination address
+ * @from: source address
+ * @n: number of bytes to copy
+ *
+ * Instrument memory accesses that happen in custom memcpy implementations. The
+ * instrumentation should be inserted before the memcpy call.
+ */
+static __always_inline void instrument_memcpy_before(void *to, const void *from,
+ unsigned long n)
+{
+ kasan_check_write(to, n);
+ kasan_check_read(from, n);
+ kcsan_check_write(to, n);
+ kcsan_check_read(from, n);
+}
+
+/**
+ * instrument_memcpy_after - add instrumentation before non-instrumented memcpy
+ * @to: destination address
+ * @from: source address
+ * @n: number of bytes to copy
+ * @left: number of bytes not copied (if known)
+ *
+ * Instrument memory accesses that happen in custom memcpy implementations. The
+ * instrumentation should be inserted after the memcpy call.
+ */
+static __always_inline void instrument_memcpy_after(void *to, const void *from,
+ unsigned long n,
+ unsigned long left)
+{
+ kmsan_memmove(to, from, n - left);
+}
+
/**
* instrument_get_user() - add instrumentation to get_user()-like macros
* @to: destination variable, may not be address-taken
Bug detection tools based on compiler instrumentation may miss memory accesses in custom memcpy implementations (such as copy_mc_to_kernel). Provide instrumentation hooks that tell KASAN, KCSAN, and KMSAN about such accesses. Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/ Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Linus Torvalds <torvalds@linux-foundation.org> --- include/linux/instrumented.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)